This project is an investigation into the pulmonary mucociliary transport function of subjects with cystic fibrosis and asthma. Tracheal mucociliary transport rates are measured by directly observing the rate of motion of Teflon markers across the tracheal mucosa through a fiberoptic bronchoscope. The rates measured in patients will be compared to those measured in normal volunteers. Variables to be studied include the nature and extent of pulmonary disease, the effect of hydration of the mucosa, and the effect of pharmacological agents.